杭州市农田蔬菜中Cu、Zn和Pb污染评价及富集特性研究

Researches on Pollution Evaluation and Enrichment Characteristics of Cu,Zn and Pb in Farmland Vegetable in Hangzhou

主要对杭州市不同蔬菜中Cu、Zn和Pb污染状况及富集特性进行了研究.结果表明:4种蔬菜(小葱,韭菜,大蒜,茄子)的可食部位和非可食部位Pb含量均远远超过食品卫生标准,样本超标率达100%,蔬菜可食部位含Cu量和含Zn量均未出现超标现象,但部分蔬菜根系出现Cu、Zn超标现象.单因子污染指数评价结果表明,4种蔬菜可食部位Cu、Zn含量均属清洁水平,而韭菜根系Cu、Zn含量和小葱Zn含量均属轻污染水平,但4种蔬菜的可食部位Pb含量及根系Pb含量均属重污染水平;综合污染指数评价结果表明,4种蔬菜的重金属污染程度均属重度污染,且污染顺序为:小葱>韭菜>大蒜>茄子.4种不同蔬菜的根系对土壤Cu、Zn、Pb及茎叶对土壤Pb均具有高富集能力,而不同蔬菜茎叶对土壤Cu、Zn多为中度富集,且不同蔬菜Pb富集系数大小顺序为:小葱>韭菜>大蒜>茄子.

The paper studies the pollution index and accumulation characteristics of copper （Cu）, zinc （Zn） and lead （Pb） in different vegetable in Hangzhou. The results show that Pb content is far beyond the standard of China National Food Sanitation Standards for Heavy Metals in both edible parts and non-edible parts of four kinds of vegetables （shallot, leek, Garlic, eggplant）, and the exceeding rate is up to 100%. Cu and Zn contents in roots of some vegetable has exceeded the standard of China National Food Sanitation Standards for Heavy Metals, although that in edible parts of vegetable are within the standard. Evaluation based on single-factor pollution index has demonstrated that Cu and Zn content are within safe levels in edible parts of the four vegetable, but Cu and Zn contents in leek root and Zn contents in shallot root are polluted lightly, moreover, it is heavily polluted by Pb in both edible parts and roots of the four vegetable. Comprehensive pollution index（PM）evaluation demonstrated that heavy metal pollution is severed in four kinds of vegetables, and the order of PM is shallot 〉leek〉Garlic〉eggplant. Besides, the roots of the four different vegetable have high accumulation ability for Cu, Zn and Pb in soils, the shoots also have high accumulation ablibity for Pb in soils although which mostly have a moderate accumulation ability for Cu, Zn in soils, moreover, the order of the accumulation coefficient for Pb in the four vegetable is shallot〉leek〉 Garlic〉 Eggplant.